Toothbrush



M. MUELLER.

TOOTHBRUSH.

APPLICATION FILED JUNE 5,1918

Patented Sept, 21, 1920 M/VE/V TOR Mai/Ola Mud/er UNITED-STATES PATENT OFFICE.

MATILDA MUELLER, or RUGBY, NORTH nexorA.

TOOTHBRUSH.

Specification 6r Letters Patent. P te t t 0 7 Application filed June 5, 1918. .Serial No. 238,339.

To all whom it may concern:

Be it known that I, MATILDA MUELLER, a subject of the King of Great'Britain, and a resident vof Rugby in the county of Pierce and State of North akota, have invented a new and Improved Toothbrush, of which the following is a' description.

My invention relates to tooth brushes, and more particularly relates to a tooth brush having separate brush backs with bristles thereon, the respective backs and the bristles thereof being so disposed as to be positioned for simultaneously cleaning a row of teeth at a side surface and at the end surface or the crowns thereof, the brush being adapted to be rocked about the general longitudinal axis thereof to position the brush for cleaning'the. inner or outer side of the teeth with the cleaning of the crowns.

The object c-f'the invention is to provide a brush'of theindicated character in which Reference is to be had to theaccompanying drawings forming a part of this specification. Figure 1 is a top yiew of a tooth-brush formed in accordance with my invention;

Fig. 2 is a side View thereof;

Fig. '3 is a cross section 1n1a plane indicated by the line 3-3, Fig, 1.'

In forming abrush in accordance with my invention a 'ha'ndle 10 of any desired shape is provided,'having transverse arms 11 at the front end thereof extending at opposite sides of the axis. Fronithe outer ends of the arms 11 separate brush backs 12 extend forwardly. Said handle, transverse arms, and brush backsv are rigid with one another, any suitable material being employed in the manufacture of these parts.

It willbeobserved that the brush backs- 1 2 arecurved longitudinally while presenting straight transverse lines at any given cross section and that the bristles of the respective backs are of decreasing length from the forward and rear ends of each back toward the-center so that the ends of the bristles .lie substantially in the same plane. It will be further noted from Figs. 3 and that the brush backs lie in general surface of the teeth simultaneously with planes approximately at right angles to each 'date the teeth A- in a manner that the ends of the bristles of one brush back may be disposed against a side'ofthe teeth, while the ends of the bristles of'the other brush back are positioned against the end surface or crowns of the teeth. Thus, the brush may -be moved back-and forth longitudinally and may be turned transversely from the outer side to the inner side of the teeth through an angle of approximately 90 degrees to successively dispose the brush for cleaning the crown and the opposite sides of the tooth or teeth.

It will be seen that a curved brush ele mentwill be presented to the inner side of arow of teeth regardless. of whether-the brush is held in the left hand or in the right hand and will conform generally to the curvature of the row of teeth while at the same time the other curved brush element is presented to the crowns of the teeth. Thus,

the longitudinal curvature of the brush backs to. give them concavo-convex form, with the convexiti es' at the front, and with the bristles of .the respective brush backs terminating approximately in planes corre sponding wi-th'two sidesof a square, promotes efliciency, and convenience in the cleaning of the/inner surface of a row of teeth simultaneously with the cleaning of the. crowns, and the curvature :does not de stroy the efficiency of eitherbrush back when the bristles thereof are presented to'the outfir t e cleaning of thecrowns',

Having thus" described my invention, I claim as new, and desire to secure by Letters Patent: A toothbrush including ahahdle, separate forwardly extending brush backs rigid therewith at the front end and disposed in planes generally at approximately right angles to each other, said brush backs being each curved-longitudinally to present a concavoconvex form with the convexities of both backs at the inner sides," and bristles "on said convex inner sides of the brush backs, the

ends of the bristles lying in planes at angles corresponding approximately with two sides outer surfaces of a row of teeth and the of a square so that either brush element other brush element be presented to the 10 constituted by a brush back and its bristles rcrownsof the teeth.

may be presented to a. row of teeth at the inner'side thereof and conform generally to MATILDA MUELLER.

its curvature and the other brush element Witnesses: presented to the crowns of the row of teeth, OTTO CHRISTIANSEN,

or one brush element be presented to the JOHN: GREBE. 

